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Monday, February 15, 2010

Of the World I had forgotten in the last 7 months

Anyone familiar with the book of patterns by the Gang of Four knows that the patterns presented in the book represent elegant solutions that have evolved over time. Unfortunately, extracting these patterns from legacy code is impossible, because nobody knew that they were supposed to be using these patterns when they wrote the legacy code. Hence, this work is a catalog of patterns for the masses. The patterns presented here represent abundant solutions that have endured over time. Enjoy reading the patterns, but please don't use them!

1) Cremational Patterns

Below is a list of five cremational patterns:

1.1 Abject PovertyThe Abject Poverty Pattern is evident in software that is so difficult to test and maintainthat doing so results in massive budget overruns.

1.2 BlinderThe Blinder Pattern is an expedient solution to a problem without regard for future changes in requirements. It is unclear as to whether the Blinder is named for the blinders worn by the software designer during the coding phase, or the desire to gouge his eyes out during the maintenance phase.

1.3 Fallacy MethodThe Fallacy method is evident in handling corner cases. The logic looks correct, but if anyone actually bothers to test it, or if acorner case occurs, the Fallacy of the logic will become known.

1.4 ProtoTryThe ProtoTry Pattern is a quick and dirty attempt to develop a working model of software. The original intent is to rewrite the ProtoTry,using lessons learned, but schedules never permit. The ProtoTry is also known as legacy code.

1.5 SimpletonThe Simpleton Pattern is an extremely complex pattern used for the most trivial of tasks. The Simpleton is an accurate indicator of the skill level of its creator.

2) De-structural Patterns

Below is a list of seven de-structural patterns.2.1 AdopterThe Adopter Pattern provides a home for orphaned functions. The result is a large family of functions that don't look anything alike, whose only relation to one another is through the Adopter.

2.2 BrigThe Brig Pattern is a container class for bad software. Also known as module.

2.3 CompromiseThe Compromise Pattern is used to balance the forces of schedule vs.quality. The result is software of inferior quality that is still late.

2.4 DetonatorThe Detonator is extremely common, but often undetected. A common example is the calculations based on a 2 digit year field. This bomb is out there, and waiting to explode!

2.5 FromageThe Fromage Pattern is often full of holes. Fromage consists of cheesy little software tricks that make portability impossible. The older this pattern gets, the riper it smells.

2.6 FlypaperThe Flypaper Pattern is written by one designer and maintained by another. The designer maintaining the Flypaper Pattern finds herself stuck, and will likely perish before getting loose.

2.7 ePoxyThe ePoxy Pattern is evident in tightly coupled software modules. As coupling between modules increases, there appears to be an epoxy bond between them.

3) Misbehavioral Patterns

Below is a list of eleven misbehavioral patterns.

3.1 Chain of Possibilities

The Chain of Possibilities Pattern is evident in big, poorly documented modules. Nobody is sure of the full extent of its functionality, but the possibilities seem endless. Also known as Non-Deterministic.

3.2 CommandoThe Commando Pattern is used to get in and out quick, and get the job done. This pattern can break any encapsulation to accomplish its mission. It takes no prisoners.

3.3 Intersperser

The Intersperser Pattern scatters pieces of functionality throughout as system, making a function impossible to test, modify, or understand.

3.4 InstigatorThe Instigator Pattern is seemingly benign, but wreaks havoc on other parts of the software system.

The Medicator Pattern is a real time hog that makes the rest of the system appear to be medicated with strong sedatives.

3.7 AbsolverThe Absolver Pattern is evident in problem ridden code developed by former employees. So many historical problems have been traced to this software that current employees can absolve their software of blame by claiming that the absolver is responsible for any problem reported. Also known as It's-not-in-my-code.

3.8 StakeThe Stake Pattern is evident in problem ridden software written by designers who have since chosen the management ladder. Although raught with problems, the manager's stake in this software is too high to allow anyone to rewrite it, as it represents the pinnacle of the manager's technical achievement.

3.9 EulogyThe Eulogy Pattern is eventually used on all projects employing the other 22 Resign Patterns. Also known as Post Mortem.

3.10 Tempest MethodThe Tempest Method is used in the last few days before software delivery. The Tempest Method is characterized by lack of comments, and introduction of several Detonator Patterns.

3.11 Visitor From HellThe Visitor From Hell Pattern is coincident with the absence of run time bounds checking on arrays. Inevitably, at least one control loopper system will have a Visitor From Hell Pattern that will overwrite critical data.